There are some people who become confused about the differences between anime and manga. Anime is considered to be a Japanese form of the cartoon by a lot of people but in Japan, anime is simply considered to be an art form coming from various parts of the world. Manga is another form of entertainment that people can usually see and read.
There are some series that are considered to be better than a manga. An example of this is Dragon Ball Z. This anime series has gotten a lot of attention because people consider it to be interesting. There are a lot of fans who would rather watch the series as compared to reading about it.
When switching from one form of media or entertainment to another, sometimes one version is better than the rest. It makes sense that books which have a lot of detail and many different stories that make you connect with it as fans may prove better than the movie version which is rushed and tends to miss important parts of the story which then alter the characters themselves.
This is the common case of manga to anime as well. But sometimes a manga will not do very well in print but the animated version will be a wild success. Some of these include anime like sword art online and dragonball Z.